Problem: Ishaan had to read articles 20 through 59 for homework tonight. If Ishaan read all of the articles he was assigned, how many articles did he read?
Explanation: Instead of counting articles 20 through 59, we can subtract 19 from each number so we instead consider articles 1 through 40. We see that Ishaan read 40 articles. Notice that he read 40 and not 39 articles.